Navigation System For Human Body In Development

The TLEMsafe model can be personalized for individual patients and surgeon can use it to enhance their preparations for surgery.

June 4, 2010

Researchers from the University of Twente's MIRA research institute, UMC St Radboud and various other institutions have developed a highly detailed computer model of the musculoskeletal system of the lower half of the human body. Surgeons can use this model to enhance their preparations for surgery, and even to "practice" these procedures in advance, using Virtual Reality. The model can be personalized for individual patients. The researchers recently received a European grant of 3 million euros for the development work.

Hip prosthesis revision surgery and operations to remove tumours can involve the loss of parts of bones or muscles. In such cases, muscles are sometimes repositioned to enhance the patient's functional abilities. When deciding exactly where to connect these muscles, surgeons usually rely on their intuition and experience. There are currently no suitable models capable of accurately predicting how the muscle will function following surgery or rehabilitation. In many cases, it is unclear whether the patient will still be able to walk normally after surgery.

Researchers from the University of Twente and various other institutions are currently developing a model that can accurately calculate the best place to connect the muscle and the best way in which to do so. MRI scans are used to personalize the model, creating a unique model for each specific patient. By using these personalized models in a Virtual Reality environment, surgeons are better able to plan surgical procedures in advance. The system can autonomously select the optimum site for muscle connection. It can also predict the consequences of specific choices. If so required, surgeons can even simulate entire operations in advance using a Virtual Reality environment.

The computer model is linked to an automated navigation system that is used during surgery. This ensures that the site selected by the system as the optimal location for muscle attachment can actually be used in the patient in question. The researchers compare this system to a satnav system. The system shows the surgeon exactly how certain muscles should be relocated in order to optimize the patient's musculoskeletal system.

According to the researchers, this system could benefit several hundred patients undergoing relatively major surgery in the Netherlands each year.

According to Prof. Nico Verdonschot and Prof. Bart Koopman, who are both members of the research team, the strength of the underlying musculoskeletal model lies in its accuracy, which is approximately five times greater than that of existing models. Uniquely, the system is based on a single, consistent dataset. This means that the body of a single individual is used as a basis (while existing models are composed of parts of different bodies). The fine detail of this individual's muscles, bones, tendons and attachments is mapped and digitized. As stated, the model is based on a consistent data set. However, an MRI scan is used to personalize the model for each patient, creating a model that is unique to the individual in question.

The model is being developed under the name TLEMsafe (TLEM stands for Twente Lower Extremity Model). This model deals only with the lower half of the body, but the same approach could ultimately be adopted for other parts of the body.

This project is the brainchild of researchers at the University of Twente. They are collaborating with UMC St Radboud (Nijmegen), the University of Warsaw (Poland) and the following companies: Brainlab A.G. (Germany), Anybody Technology A/S (Denmark) and Materialize N.V. (Belgium).

This joint venture has recently been awarded a substantial European grant of three million euros. Almost one million euros of this money will be used to support research at the University of Twente.

The researchers expect their model to be ready in four years' time. It will then be subjected to clinical tests. However, the researchers believe that it will be possible to make practical use of various piecemeal solutions before then.